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Mercury is one of the most toxic elements in nature, the application is very wide, volatile, very harmful to human health. Different forms of mercury compounds toxicity differences larger evaluation of mercury in the environment harmful levels of total mercury can not accurately reflect the differences of the various forms of biological toxicity of mercury, and should therefore be carried out qualitative and quantitative analysis of the various forms of mercury. Environment chosen for this study the three most common form of mercury (Hg (Ⅱ), MeHg and EtHg) as the object of study, for the first time established the the HPLC-VG-AFS Determination of different forms of mercury vegetables, results show that: 1 cloud point extraction and whirlpool mixed extract than two pretreatment methods, whirlpool mixing easy to operate and has a higher extraction efficiency. 2 Instrument conditions were optimized includes three aspects: (1) the optimization of the separation conditions: 5% acetonitrile (HPLC grade, v / v) -0.462% ammonium acetate (m / v) -0.12% L-cysteine ??( m / v) as the mobile phase flow rate was 1.0mL/min select C18 reverse phase column chromatography on silica gel (Venusil MP C18, 4.6mm × 150mm, 5μm) the best separation separation column, Mercury, and the peak-type symmetry . (2) the optimization of the gas generating conditions: oxidant concentration of 1.0% K2S2O8 (m / v) 0.5% KOH (m / v), the reducing agent is: 1.5% KBH4 for (m / v), 0.5% KOH (m / v), contained stream HCl concentration of 7% (v / v), the online UV digestion (UV) when the signal to noise ratio to achieve the best. (3) optimization of detection conditions: mercury hollow cathode lamp lamp current of 30 mA, the photomultiplier tube negative high voltage 310 V, the atomizer temperature of 200 ° C, a height of 10 mm, carrier gas flow rate of 400 mL / min, shielded The flow rate was 600 mL / min SNR optimal. 3 to evaluate the determination of the three forms of mercury detection limit of Hg (Ⅱ) 0.14μg / L, MeHg 0.05μg / L, EtHg0.12μg / L, method of standard addition recoveries between 75% -110%, 10μg / L (Hg), the form of mercury standard solution, continuous injection seven times, the relative standard deviation of retention time and peak area were: Hg (II) 3.43%, 2.75%, MeHg2.24%, 4.07%, EtHg1 .38%, 3.28%; analysis of the measurement results of the same vegetable samples spinach, the relative standard deviation of the measured values ??of the three forms of mercury Hg (II) 2.26% MeHg2.23%, EtHg3.06 of the above The relative standard deviation is controlled within 5%. The peak area of ??the three forms of mercury concentration showed a good linear relationship, the correlation coefficients were greater than 0.999. 4 applications (1) method vegetables detection: the common market vegetables terrestrial and aquatic vegetables detect drawn: terrestrial vegetables basically there is no mercury pollution, only a few samples detected mercury species, but the sample mainly inorganic mercury, followed by methylmercury, ethylmercury was not detected in the amount of mercury in aquatic vegetables higher form of inorganic mercury. (2) the application of the method in the detection of rice, herbs, and aquatic: HCl concentration in the extractant becomes 10%, ceteris paribus. The results showed that the rice mercury to methylmercury, followed by inorganic mercury, not ethyl mercury detection; Chinese herbal medicines in the form of mercury substances detected; aquatic mercury methylmercury form of existence only.
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